Electricity is the flow of electrical power or charge. It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. The energy sources we use to generate electricity can be renewable or non-renewable, but electricity itself is neither renewable or non-renewable.
How to generate electricity?
A generator is a device that converts mechanical energy into electrical energy. The process is based on the relationship between magnetism and electricity. In 1831, Faraday discovered that when a magnet is moved inside a coil of wire, electrical current flows in the wire.
An electric utility power station uses either a turbine, engine, water wheel, or other similar machine to drive an electric generator or a device that converts mechanical or chemical energy to generate electricity. Steam turbines, internal combustion engines, gas combustion turbines, water turbines, and wind turbines are the most common methods to generate electricity. Most power plants are about 35 percent efficient.
Most of the electricity in the United States is produced in steam turbines. A turbine converts the kinetic energy of a moving fluid (liquid or gas) to mechanical energy. Steam turbines have a series of blades mounted on a shaft against which steam is forced, thus rotating the shaft connected to the generator. In a fossil-fueled steam turbine, the fuel is burned in a furnace to heat water in a boiler to produce steam. Coal, petroleum (oil), and natural gas are burned in large furnaces to heat water to make steam that in turn pushes on the blades of a turbine.
Electrolysis
Water is a compound made of two elements. Hydrogen and oxygen. When an electric current is passed through water, it splits into these two elements. This is an effective way of extracting hydrogen. Now, how clean your energy is, is dependent on the electricity you use. If the electricity you use is renewable then your hydrogen is clean energy.
Electrolysis has various other usages as well. One of its most common uses is to coat one metal with another. For example, it can be used to coat copper with gold.
Renewable Liquid Reforming
Ethanol is a renewable liquid fuel. It can be used to manufacture hydrogen by treating it with high-temperature steam.
Fermentation
As has been pointed out before, biomass or your organic wastes are extremely good for creating hydrogen energy. However, to make this economically viable, we must depend on local materials and supply of biomass. This is something that needs to be considered. Directly converting biomass to hydrogen energy can be challenging and research is continuously carried out on this topic.
Some hydrogen production methods that scientists are currently working on are:
- High-Temperature Water-Splitting
- Photobiological Water-Splitting
- Photoelectrochemical Water-Splitting
(Source: http://www.ei.lehigh.edu/learners/energy/readings/electricity.pdf)
Nuclear Power
Matter is made out of atoms and the major mass of the atom is mainly concentrated in the center also known as the nucleus. The remaining mass is in the electrons that surround the nucleus. Under some particular happenings, the nucleus of the atom results in two different atoms, post the process of splitting. During this, a part of the mass of the atom gets converted into energy that follows the Einstein’s formula given by E = mc2, where m is the mass and c is the speed of light. It was discovered, in the 20th century, that this energy could be used in weaponry thus giving rise to nuclear bombs. This was also transferred to the public with businesses making commercial plans to develop and deploy electricity.
Water Generates Electricity
So, how exactly do we generate electricity from water? This usually occurs through a hydroelectric dam that is built along a flowing waterway. Think of the water at Niagara. The water flowing over the falls is travelling faster than the water approaching the falls. As water travels downhill, it picks up speed and power.
To take advantage of this, dams are constructed along the waterway where there is a large elevation drop. This is exactly why you wouldn’t expect to find dams in flat places like Florida, but would expect to find them in the hilly, mountainous regions of the Southwest U.S.
Like going down a slide at the playground, water is pulled downhill by gravity and picks up speed as it goes (you’re moving faster at the bottom of the slide than at the top, right?). Inside the dam are turbines that get spun by the moving water – similar to how a pinwheel gets spun by the wind blowing by.
The spinning turbine shafts are connected to a generator, and the spinning of the turbines themselves creates electricity inside the generator. The generator is connected to power lines, which transmit the electricity to homes and buildings just like they do with coal-fired and natural gas power plants.
Just like wind blowing past the pinwheel is not affected by the pinwheel itself, water flowing by the turbines is not affected as it passes through the dam. It flows on downstream as if nothing has happened. You can see why this is such a valuable and widely used energy resource all around the world!
Wind Power
Wind power is the use of air flow through wind turbines to mechanically power generators for electric power. Wind power, as an alternative to burning fossil fuels, is plentiful, renewable, widely distributed, clean, produces no greenhouse gas emissions during operation, consumes no water, and uses the little land. The net effects on the environment are far less problematic than those of non-renewable power sources.
Since wind speeds vary a lot over the year and even on any given day, it is not feasible to power the entire grid using just wind energy. It is therefore used in conjunction with other electric power sources to give a reliable power supply. A wind farm is a group of wind turbines in the same location used for the production of electric power. A large wind farm may consist of several hundred individual wind turbines distributed over an extended area, but the land between the turbines may be used for agricultural or other purposes. For example, Gansu Wind Farm, the largest wind farm in the world, has several thousand turbines. A wind farm may also be located offshore.
